1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (C) 2011-2016 Universita` di Pisa
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 /*
31 *
32 * Functions and macros to manipulate netmap structures and packets
33 * in userspace. See netmap(4) for more information.
34 *
35 * The address of the struct netmap_if, say nifp, is computed from the
36 * value returned from ioctl(.., NIOCREG, ...) and the mmap region:
37 * ioctl(fd, NIOCREG, &req);
38 * mem = mmap(0, ... );
39 * nifp = NETMAP_IF(mem, req.nr_nifp);
40 * (so simple, we could just do it manually)
41 *
42 * From there:
43 * struct netmap_ring *NETMAP_TXRING(nifp, index)
44 * struct netmap_ring *NETMAP_RXRING(nifp, index)
45 * we can access ring->cur, ring->head, ring->tail, etc.
46 *
47 * ring->slot[i] gives us the i-th slot (we can access
48 * directly len, flags, buf_idx)
49 *
50 * char *buf = NETMAP_BUF(ring, x) returns a pointer to
51 * the buffer numbered x
52 *
53 * All ring indexes (head, cur, tail) should always move forward.
54 * To compute the next index in a circular ring you can use
55 * i = nm_ring_next(ring, i);
56 *
57 * To ease porting apps from pcap to netmap we supply a few functions
58 * that can be called to open, close, read and write on netmap in a way
59 * similar to libpcap. Note that the read/write function depend on
60 * an ioctl()/select()/poll() being issued to refill rings or push
61 * packets out.
62 *
63 * In order to use these, include #define NETMAP_WITH_LIBS
64 * in the source file that invokes these functions.
65 */
66
67 #ifndef _NET_NETMAP_USER_H_
68 #define _NET_NETMAP_USER_H_
69
70 #define NETMAP_DEVICE_NAME "/dev/netmap"
71
72 #ifdef __CYGWIN__
73 /*
74 * we can compile userspace apps with either cygwin or msvc,
75 * and we use _WIN32 to identify windows specific code
76 */
77 #ifndef _WIN32
78 #define _WIN32
79 #endif /* _WIN32 */
80
81 #endif /* __CYGWIN__ */
82
83 #ifdef _WIN32
84 #undef NETMAP_DEVICE_NAME
85 #define NETMAP_DEVICE_NAME "/proc/sys/DosDevices/Global/netmap"
86 #include <windows.h>
87 #include <WinDef.h>
88 #include <sys/cygwin.h>
89 #endif /* _WIN32 */
90
91 #include <stdint.h>
92 #include <sys/socket.h> /* apple needs sockaddr */
93 #include <net/if.h> /* IFNAMSIZ */
94 #include <ctype.h>
95 #include <string.h> /* memset */
96 #include <sys/time.h> /* gettimeofday */
97
98 #ifndef likely
99 #define likely(x) __builtin_expect(!!(x), 1)
100 #define unlikely(x) __builtin_expect(!!(x), 0)
101 #endif /* likely and unlikely */
102
103 #include <net/netmap.h>
104
105 /* helper macro */
106 #define _NETMAP_OFFSET(type, ptr, offset) \
107 ((type)(void *)((char *)(ptr) + (offset)))
108
109 #define NETMAP_IF(_base, _ofs) _NETMAP_OFFSET(struct netmap_if *, _base, _ofs)
110
111 #define NETMAP_TXRING(nifp, index) _NETMAP_OFFSET(struct netmap_ring *, \
112 nifp, (nifp)->ring_ofs[index] )
113
114 #define NETMAP_RXRING(nifp, index) _NETMAP_OFFSET(struct netmap_ring *, \
115 nifp, (nifp)->ring_ofs[index + (nifp)->ni_tx_rings + \
116 (nifp)->ni_host_tx_rings] )
117
118 #define NETMAP_BUF(ring, index) \
119 ((char *)(ring) + (ring)->buf_ofs + ((size_t)(index)*(ring)->nr_buf_size))
120
121 #define NETMAP_BUF_IDX(ring, buf) \
122 ( ((char *)(buf) - ((char *)(ring) + (ring)->buf_ofs) ) / \
123 (ring)->nr_buf_size )
124
125 /* read the offset field in a ring's slot */
126 #define NETMAP_ROFFSET(ring, slot) \
127 ((slot)->ptr & (ring)->offset_mask)
128
129 /* update the offset field in a ring's slot */
130 #define NETMAP_WOFFSET(ring, slot, offset) \
131 do { (slot)->ptr = ((slot)->ptr & ~(ring)->offset_mask) | \
132 ((offset) & (ring)->offset_mask); } while (0)
133
134 /* obtain the start of the buffer pointed to by a ring's slot, taking the
135 * offset field into account
136 */
137 #define NETMAP_BUF_OFFSET(ring, slot) \
138 (NETMAP_BUF(ring, (slot)->buf_idx) + NETMAP_ROFFSET(ring, slot))
139
140
141 static inline uint32_t
nm_ring_next(struct netmap_ring * r,uint32_t i)142 nm_ring_next(struct netmap_ring *r, uint32_t i)
143 {
144 return ( unlikely(i + 1 == r->num_slots) ? 0 : i + 1);
145 }
146
147
148 /*
149 * Return 1 if we have pending transmissions in the tx ring.
150 * When everything is complete ring->head = ring->tail + 1 (modulo ring size)
151 */
152 static inline int
nm_tx_pending(struct netmap_ring * r)153 nm_tx_pending(struct netmap_ring *r)
154 {
155 return nm_ring_next(r, r->tail) != r->head;
156 }
157
158 /* Compute the number of slots available in the netmap ring. We use
159 * ring->head as explained in the comment above nm_ring_empty(). */
160 static inline uint32_t
nm_ring_space(struct netmap_ring * ring)161 nm_ring_space(struct netmap_ring *ring)
162 {
163 int ret = ring->tail - ring->head;
164 if (ret < 0)
165 ret += ring->num_slots;
166 return ret;
167 }
168
169 #ifndef ND /* debug macros */
170 /* debug support */
171 #define ND(_fmt, ...) do {} while(0)
172 #define D(_fmt, ...) \
173 do { \
174 struct timeval _t0; \
175 gettimeofday(&_t0, NULL); \
176 fprintf(stderr, "%03d.%06d %s [%d] " _fmt "\n", \
177 (int)(_t0.tv_sec % 1000), (int)_t0.tv_usec, \
178 __FUNCTION__, __LINE__, ##__VA_ARGS__); \
179 } while (0)
180
181 /* Rate limited version of "D", lps indicates how many per second */
182 #define RD(lps, format, ...) \
183 do { \
184 static int __t0, __cnt; \
185 struct timeval __xxts; \
186 gettimeofday(&__xxts, NULL); \
187 if (__t0 != __xxts.tv_sec) { \
188 __t0 = __xxts.tv_sec; \
189 __cnt = 0; \
190 } \
191 if (__cnt++ < lps) { \
192 D(format, ##__VA_ARGS__); \
193 } \
194 } while (0)
195 #endif
196
197 /*
198 * this is a slightly optimized copy routine which rounds
199 * to multiple of 64 bytes and is often faster than dealing
200 * with other odd sizes. We assume there is enough room
201 * in the source and destination buffers.
202 */
203 static inline void
nm_pkt_copy(const void * _src,void * _dst,int l)204 nm_pkt_copy(const void *_src, void *_dst, int l)
205 {
206 const uint64_t *src = (const uint64_t *)_src;
207 uint64_t *dst = (uint64_t *)_dst;
208
209 if (unlikely(l >= 1024 || l % 64)) {
210 memcpy(dst, src, l);
211 return;
212 }
213 for (; likely(l > 0); l-=64) {
214 *dst++ = *src++;
215 *dst++ = *src++;
216 *dst++ = *src++;
217 *dst++ = *src++;
218 *dst++ = *src++;
219 *dst++ = *src++;
220 *dst++ = *src++;
221 *dst++ = *src++;
222 }
223 }
224
225 #ifdef NETMAP_WITH_LIBS
226 /*
227 * Support for simple I/O libraries.
228 * Include other system headers required for compiling this.
229 */
230
231 #ifndef HAVE_NETMAP_WITH_LIBS
232 #define HAVE_NETMAP_WITH_LIBS
233
234 #include <stdio.h>
235 #include <sys/time.h>
236 #include <sys/mman.h>
237 #include <sys/ioctl.h>
238 #include <sys/errno.h> /* EINVAL */
239 #include <fcntl.h> /* O_RDWR */
240 #include <unistd.h> /* close() */
241 #include <signal.h>
242 #include <stdlib.h>
243
244 struct nm_pkthdr { /* first part is the same as pcap_pkthdr */
245 struct timeval ts;
246 uint32_t caplen;
247 uint32_t len;
248
249 uint64_t flags; /* NM_MORE_PKTS etc */
250 #define NM_MORE_PKTS 1
251 struct nm_desc *d;
252 struct netmap_slot *slot;
253 uint8_t *buf;
254 };
255
256 struct nm_stat { /* same as pcap_stat */
257 u_int ps_recv;
258 u_int ps_drop;
259 u_int ps_ifdrop;
260 #ifdef WIN32 /* XXX or _WIN32 ? */
261 u_int bs_capt;
262 #endif /* WIN32 */
263 };
264
265 #define NM_ERRBUF_SIZE 512
266
267 struct nm_desc {
268 struct nm_desc *self; /* point to self if netmap. */
269 int fd;
270 void *mem;
271 size_t memsize;
272 int done_mmap; /* set if mem is the result of mmap */
273 struct netmap_if * const nifp;
274 uint16_t first_tx_ring, last_tx_ring, cur_tx_ring;
275 uint16_t first_rx_ring, last_rx_ring, cur_rx_ring;
276 struct nmreq req; /* also contains the nr_name = ifname */
277 struct nm_pkthdr hdr;
278
279 /*
280 * The memory contains netmap_if, rings and then buffers.
281 * Given a pointer (e.g. to nm_inject) we can compare with
282 * mem/buf_start/buf_end to tell if it is a buffer or
283 * some other descriptor in our region.
284 * We also store a pointer to some ring as it helps in the
285 * translation from buffer indexes to addresses.
286 */
287 struct netmap_ring * const some_ring;
288 void * const buf_start;
289 void * const buf_end;
290 /* parameters from pcap_open_live */
291 int snaplen;
292 int promisc;
293 int to_ms;
294 char *errbuf;
295
296 /* save flags so we can restore them on close */
297 uint32_t if_flags;
298 uint32_t if_reqcap;
299 uint32_t if_curcap;
300
301 struct nm_stat st;
302 char msg[NM_ERRBUF_SIZE];
303 };
304
305 /*
306 * when the descriptor is open correctly, d->self == d
307 * Eventually we should also use some magic number.
308 */
309 #define P2NMD(p) ((const struct nm_desc *)(p))
310 #define IS_NETMAP_DESC(d) ((d) && P2NMD(d)->self == P2NMD(d))
311 #define NETMAP_FD(d) (P2NMD(d)->fd)
312
313 /*
314 * The callback, invoked on each received packet. Same as libpcap
315 */
316 typedef void (*nm_cb_t)(u_char *, const struct nm_pkthdr *, const u_char *d);
317
318 /*
319 *--- the pcap-like API ---
320 *
321 * nm_open() opens a file descriptor, binds to a port and maps memory.
322 *
323 * ifname (netmap:foo or vale:foo) is the port name
324 * a suffix can indicate the following:
325 * ^ bind the host (sw) ring pair
326 * * bind host and NIC ring pairs
327 * -NN bind individual NIC ring pair
328 * {NN bind master side of pipe NN
329 * }NN bind slave side of pipe NN
330 * a suffix starting with / and the following flags,
331 * in any order:
332 * x exclusive access
333 * z zero copy monitor (both tx and rx)
334 * t monitor tx side (copy monitor)
335 * r monitor rx side (copy monitor)
336 * R bind only RX ring(s)
337 * T bind only TX ring(s)
338 *
339 * req provides the initial values of nmreq before parsing ifname.
340 * Remember that the ifname parsing will override the ring
341 * number in nm_ringid, and part of nm_flags;
342 * flags special functions, normally 0
343 * indicates which fields of *arg are significant
344 * arg special functions, normally NULL
345 * if passed a netmap_desc with mem != NULL,
346 * use that memory instead of mmap.
347 */
348
349 static struct nm_desc *nm_open(const char *ifname, const struct nmreq *req,
350 uint64_t flags, const struct nm_desc *arg);
351
352 /*
353 * nm_open can import some fields from the parent descriptor.
354 * These flags control which ones.
355 * Also in flags you can specify NETMAP_NO_TX_POLL and NETMAP_DO_RX_POLL,
356 * which set the initial value for these flags.
357 * Note that the 16 low bits of the flags are reserved for data
358 * that may go into the nmreq.
359 */
360 enum {
361 NM_OPEN_NO_MMAP = 0x040000, /* reuse mmap from parent */
362 NM_OPEN_IFNAME = 0x080000, /* nr_name, nr_ringid, nr_flags */
363 NM_OPEN_ARG1 = 0x100000,
364 NM_OPEN_ARG2 = 0x200000,
365 NM_OPEN_ARG3 = 0x400000,
366 NM_OPEN_RING_CFG = 0x800000, /* tx|rx rings|slots */
367 };
368
369
370 /*
371 * nm_close() closes and restores the port to its previous state
372 */
373
374 static int nm_close(struct nm_desc *);
375
376 /*
377 * nm_mmap() do mmap or inherit from parent if the nr_arg2
378 * (memory block) matches.
379 */
380
381 static int nm_mmap(struct nm_desc *, const struct nm_desc *);
382
383 /*
384 * nm_inject() is the same as pcap_inject()
385 * nm_dispatch() is the same as pcap_dispatch()
386 * nm_nextpkt() is the same as pcap_next()
387 */
388
389 static int nm_inject(struct nm_desc *, const void *, size_t);
390 static int nm_dispatch(struct nm_desc *, int, nm_cb_t, u_char *);
391 static u_char *nm_nextpkt(struct nm_desc *, struct nm_pkthdr *);
392
393 #ifdef _WIN32
394
395 intptr_t _get_osfhandle(int); /* defined in io.h in windows */
396
397 /*
398 * In windows we do not have yet native poll support, so we keep track
399 * of file descriptors associated to netmap ports to emulate poll on
400 * them and fall back on regular poll on other file descriptors.
401 */
402 struct win_netmap_fd_list {
403 struct win_netmap_fd_list *next;
404 int win_netmap_fd;
405 HANDLE win_netmap_handle;
406 };
407
408 /*
409 * list head containing all the netmap opened fd and their
410 * windows HANDLE counterparts
411 */
412 static struct win_netmap_fd_list *win_netmap_fd_list_head;
413
414 static void
win_insert_fd_record(int fd)415 win_insert_fd_record(int fd)
416 {
417 struct win_netmap_fd_list *curr;
418
419 for (curr = win_netmap_fd_list_head; curr; curr = curr->next) {
420 if (fd == curr->win_netmap_fd) {
421 return;
422 }
423 }
424 curr = calloc(1, sizeof(*curr));
425 curr->next = win_netmap_fd_list_head;
426 curr->win_netmap_fd = fd;
427 curr->win_netmap_handle = IntToPtr(_get_osfhandle(fd));
428 win_netmap_fd_list_head = curr;
429 }
430
431 void
win_remove_fd_record(int fd)432 win_remove_fd_record(int fd)
433 {
434 struct win_netmap_fd_list *curr = win_netmap_fd_list_head;
435 struct win_netmap_fd_list *prev = NULL;
436 for (; curr ; prev = curr, curr = curr->next) {
437 if (fd != curr->win_netmap_fd)
438 continue;
439 /* found the entry */
440 if (prev == NULL) { /* we are freeing the first entry */
441 win_netmap_fd_list_head = curr->next;
442 } else {
443 prev->next = curr->next;
444 }
445 free(curr);
446 break;
447 }
448 }
449
450
451 HANDLE
win_get_netmap_handle(int fd)452 win_get_netmap_handle(int fd)
453 {
454 struct win_netmap_fd_list *curr;
455
456 for (curr = win_netmap_fd_list_head; curr; curr = curr->next) {
457 if (fd == curr->win_netmap_fd) {
458 return curr->win_netmap_handle;
459 }
460 }
461 return NULL;
462 }
463
464 /*
465 * we need to wrap ioctl and mmap, at least for the netmap file descriptors
466 */
467
468 /*
469 * use this function only from netmap_user.h internal functions
470 * same as ioctl, returns 0 on success and -1 on error
471 */
472 static int
win_nm_ioctl_internal(HANDLE h,int32_t ctlCode,void * arg)473 win_nm_ioctl_internal(HANDLE h, int32_t ctlCode, void *arg)
474 {
475 DWORD bReturn = 0, szIn, szOut;
476 BOOL ioctlReturnStatus;
477 void *inParam = arg, *outParam = arg;
478
479 switch (ctlCode) {
480 case NETMAP_POLL:
481 szIn = sizeof(POLL_REQUEST_DATA);
482 szOut = sizeof(POLL_REQUEST_DATA);
483 break;
484 case NETMAP_MMAP:
485 szIn = 0;
486 szOut = sizeof(void*);
487 inParam = NULL; /* nothing on input */
488 break;
489 case NIOCTXSYNC:
490 case NIOCRXSYNC:
491 szIn = 0;
492 szOut = 0;
493 break;
494 case NIOCREGIF:
495 szIn = sizeof(struct nmreq);
496 szOut = sizeof(struct nmreq);
497 break;
498 case NIOCCONFIG:
499 D("unsupported NIOCCONFIG!");
500 return -1;
501
502 default: /* a regular ioctl */
503 D("invalid ioctl %x on netmap fd", ctlCode);
504 return -1;
505 }
506
507 ioctlReturnStatus = DeviceIoControl(h,
508 ctlCode, inParam, szIn,
509 outParam, szOut,
510 &bReturn, NULL);
511 // XXX note windows returns 0 on error or async call, 1 on success
512 // we could call GetLastError() to figure out what happened
513 return ioctlReturnStatus ? 0 : -1;
514 }
515
516 /*
517 * this function is what must be called from user-space programs
518 * same as ioctl, returns 0 on success and -1 on error
519 */
520 static int
win_nm_ioctl(int fd,int32_t ctlCode,void * arg)521 win_nm_ioctl(int fd, int32_t ctlCode, void *arg)
522 {
523 HANDLE h = win_get_netmap_handle(fd);
524
525 if (h == NULL) {
526 return ioctl(fd, ctlCode, arg);
527 } else {
528 return win_nm_ioctl_internal(h, ctlCode, arg);
529 }
530 }
531
532 #define ioctl win_nm_ioctl /* from now on, within this file ... */
533
534 /*
535 * We cannot use the native mmap on windows
536 * The only parameter used is "fd", the other ones are just declared to
537 * make this signature comparable to the FreeBSD/Linux one
538 */
539 static void *
win32_mmap_emulated(void * addr,size_t length,int prot,int flags,int fd,int32_t offset)540 win32_mmap_emulated(void *addr, size_t length, int prot, int flags, int fd, int32_t offset)
541 {
542 HANDLE h = win_get_netmap_handle(fd);
543
544 if (h == NULL) {
545 return mmap(addr, length, prot, flags, fd, offset);
546 } else {
547 MEMORY_ENTRY ret;
548
549 return win_nm_ioctl_internal(h, NETMAP_MMAP, &ret) ?
550 NULL : ret.pUsermodeVirtualAddress;
551 }
552 }
553
554 #define mmap win32_mmap_emulated
555
556 #include <sys/poll.h> /* XXX needed to use the structure pollfd */
557
558 static int
win_nm_poll(struct pollfd * fds,int nfds,int timeout)559 win_nm_poll(struct pollfd *fds, int nfds, int timeout)
560 {
561 HANDLE h;
562
563 if (nfds != 1 || fds == NULL || (h = win_get_netmap_handle(fds->fd)) == NULL) {;
564 return poll(fds, nfds, timeout);
565 } else {
566 POLL_REQUEST_DATA prd;
567
568 prd.timeout = timeout;
569 prd.events = fds->events;
570
571 win_nm_ioctl_internal(h, NETMAP_POLL, &prd);
572 if ((prd.revents == POLLERR) || (prd.revents == STATUS_TIMEOUT)) {
573 return -1;
574 }
575 return 1;
576 }
577 }
578
579 #define poll win_nm_poll
580
581 static int
win_nm_open(char * pathname,int flags)582 win_nm_open(char* pathname, int flags)
583 {
584
585 if (strcmp(pathname, NETMAP_DEVICE_NAME) == 0) {
586 int fd = open(NETMAP_DEVICE_NAME, O_RDWR);
587 if (fd < 0) {
588 return -1;
589 }
590
591 win_insert_fd_record(fd);
592 return fd;
593 } else {
594 return open(pathname, flags);
595 }
596 }
597
598 #define open win_nm_open
599
600 static int
win_nm_close(int fd)601 win_nm_close(int fd)
602 {
603 if (fd != -1) {
604 close(fd);
605 if (win_get_netmap_handle(fd) != NULL) {
606 win_remove_fd_record(fd);
607 }
608 }
609 return 0;
610 }
611
612 #define close win_nm_close
613
614 #endif /* _WIN32 */
615
616 static int
nm_is_identifier(const char * s,const char * e)617 nm_is_identifier(const char *s, const char *e)
618 {
619 for (; s != e; s++) {
620 if (!isalnum(*s) && *s != '_') {
621 return 0;
622 }
623 }
624
625 return 1;
626 }
627
628 #define MAXERRMSG 80
629 static int
nm_parse(const char * ifname,struct nm_desc * d,char * err)630 nm_parse(const char *ifname, struct nm_desc *d, char *err)
631 {
632 int is_vale;
633 const char *port = NULL;
634 const char *vpname = NULL;
635 u_int namelen;
636 uint32_t nr_ringid = 0, nr_flags;
637 char errmsg[MAXERRMSG] = "", *tmp;
638 long num;
639 uint16_t nr_arg2 = 0;
640 enum { P_START, P_RNGSFXOK, P_GETNUM, P_FLAGS, P_FLAGSOK, P_MEMID } p_state;
641
642 errno = 0;
643
644 is_vale = (ifname[0] == 'v');
645 if (is_vale) {
646 port = index(ifname, ':');
647 if (port == NULL) {
648 snprintf(errmsg, MAXERRMSG,
649 "missing ':' in vale name");
650 goto fail;
651 }
652
653 if (!nm_is_identifier(ifname + 4, port)) {
654 snprintf(errmsg, MAXERRMSG, "invalid bridge name");
655 goto fail;
656 }
657
658 vpname = ++port;
659 } else {
660 ifname += 7;
661 port = ifname;
662 }
663
664 /* scan for a separator */
665 for (; *port && !index("-*^{}/@", *port); port++)
666 ;
667
668 if (is_vale && !nm_is_identifier(vpname, port)) {
669 snprintf(errmsg, MAXERRMSG, "invalid bridge port name");
670 goto fail;
671 }
672
673 namelen = port - ifname;
674 if (namelen >= sizeof(d->req.nr_name)) {
675 snprintf(errmsg, MAXERRMSG, "name too long");
676 goto fail;
677 }
678 memcpy(d->req.nr_name, ifname, namelen);
679 d->req.nr_name[namelen] = '\0';
680
681 p_state = P_START;
682 nr_flags = NR_REG_ALL_NIC; /* default for no suffix */
683 while (*port) {
684 switch (p_state) {
685 case P_START:
686 switch (*port) {
687 case '^': /* only SW ring */
688 nr_flags = NR_REG_SW;
689 p_state = P_RNGSFXOK;
690 break;
691 case '*': /* NIC and SW */
692 nr_flags = NR_REG_NIC_SW;
693 p_state = P_RNGSFXOK;
694 break;
695 case '-': /* one NIC ring pair */
696 nr_flags = NR_REG_ONE_NIC;
697 p_state = P_GETNUM;
698 break;
699 case '{': /* pipe (master endpoint) */
700 nr_flags = NR_REG_PIPE_MASTER;
701 p_state = P_GETNUM;
702 break;
703 case '}': /* pipe (slave endpoint) */
704 nr_flags = NR_REG_PIPE_SLAVE;
705 p_state = P_GETNUM;
706 break;
707 case '/': /* start of flags */
708 p_state = P_FLAGS;
709 break;
710 case '@': /* start of memid */
711 p_state = P_MEMID;
712 break;
713 default:
714 snprintf(errmsg, MAXERRMSG, "unknown modifier: '%c'", *port);
715 goto fail;
716 }
717 port++;
718 break;
719 case P_RNGSFXOK:
720 switch (*port) {
721 case '/':
722 p_state = P_FLAGS;
723 break;
724 case '@':
725 p_state = P_MEMID;
726 break;
727 default:
728 snprintf(errmsg, MAXERRMSG, "unexpected character: '%c'", *port);
729 goto fail;
730 }
731 port++;
732 break;
733 case P_GETNUM:
734 num = strtol(port, &tmp, 10);
735 if (num < 0 || num >= NETMAP_RING_MASK) {
736 snprintf(errmsg, MAXERRMSG, "'%ld' out of range [0, %d)",
737 num, NETMAP_RING_MASK);
738 goto fail;
739 }
740 port = tmp;
741 nr_ringid = num & NETMAP_RING_MASK;
742 p_state = P_RNGSFXOK;
743 break;
744 case P_FLAGS:
745 case P_FLAGSOK:
746 if (*port == '@') {
747 port++;
748 p_state = P_MEMID;
749 break;
750 }
751 switch (*port) {
752 case 'x':
753 nr_flags |= NR_EXCLUSIVE;
754 break;
755 case 'z':
756 nr_flags |= NR_ZCOPY_MON;
757 break;
758 case 't':
759 nr_flags |= NR_MONITOR_TX;
760 break;
761 case 'r':
762 nr_flags |= NR_MONITOR_RX;
763 break;
764 case 'R':
765 nr_flags |= NR_RX_RINGS_ONLY;
766 break;
767 case 'T':
768 nr_flags |= NR_TX_RINGS_ONLY;
769 break;
770 default:
771 snprintf(errmsg, MAXERRMSG, "unrecognized flag: '%c'", *port);
772 goto fail;
773 }
774 port++;
775 p_state = P_FLAGSOK;
776 break;
777 case P_MEMID:
778 if (nr_arg2 != 0) {
779 snprintf(errmsg, MAXERRMSG, "double setting of memid");
780 goto fail;
781 }
782 num = strtol(port, &tmp, 10);
783 if (num <= 0) {
784 snprintf(errmsg, MAXERRMSG, "invalid memid %ld, must be >0", num);
785 goto fail;
786 }
787 port = tmp;
788 nr_arg2 = num;
789 p_state = P_RNGSFXOK;
790 break;
791 }
792 }
793 if (p_state != P_START && p_state != P_RNGSFXOK && p_state != P_FLAGSOK) {
794 snprintf(errmsg, MAXERRMSG, "unexpected end of port name");
795 goto fail;
796 }
797 ND("flags: %s %s %s %s",
798 (nr_flags & NR_EXCLUSIVE) ? "EXCLUSIVE" : "",
799 (nr_flags & NR_ZCOPY_MON) ? "ZCOPY_MON" : "",
800 (nr_flags & NR_MONITOR_TX) ? "MONITOR_TX" : "",
801 (nr_flags & NR_MONITOR_RX) ? "MONITOR_RX" : "");
802
803 d->req.nr_flags |= nr_flags;
804 d->req.nr_ringid |= nr_ringid;
805 d->req.nr_arg2 = nr_arg2;
806
807 d->self = d;
808
809 return 0;
810 fail:
811 if (!errno)
812 errno = EINVAL;
813 if (err)
814 strncpy(err, errmsg, MAXERRMSG);
815 return -1;
816 }
817
818 /*
819 * Try to open, return descriptor if successful, NULL otherwise.
820 * An invalid netmap name will return errno = 0;
821 * You can pass a pointer to a pre-filled nm_desc to add special
822 * parameters. Flags is used as follows
823 * NM_OPEN_NO_MMAP use the memory from arg, only XXX avoid mmap
824 * if the nr_arg2 (memory block) matches.
825 * NM_OPEN_ARG1 use req.nr_arg1 from arg
826 * NM_OPEN_ARG2 use req.nr_arg2 from arg
827 * NM_OPEN_RING_CFG user ring config from arg
828 */
829 static struct nm_desc *
nm_open(const char * ifname,const struct nmreq * req,uint64_t new_flags,const struct nm_desc * arg)830 nm_open(const char *ifname, const struct nmreq *req,
831 uint64_t new_flags, const struct nm_desc *arg)
832 {
833 struct nm_desc *d = NULL;
834 const struct nm_desc *parent = arg;
835 char errmsg[MAXERRMSG] = "";
836 uint32_t nr_reg;
837
838 if (strncmp(ifname, "netmap:", 7) &&
839 strncmp(ifname, NM_BDG_NAME, strlen(NM_BDG_NAME))) {
840 errno = 0; /* name not recognised, not an error */
841 return NULL;
842 }
843
844 d = (struct nm_desc *)calloc(1, sizeof(*d));
845 if (d == NULL) {
846 snprintf(errmsg, MAXERRMSG, "nm_desc alloc failure");
847 errno = ENOMEM;
848 return NULL;
849 }
850 d->self = d; /* set this early so nm_close() works */
851 d->fd = open(NETMAP_DEVICE_NAME, O_RDWR);
852 if (d->fd < 0) {
853 snprintf(errmsg, MAXERRMSG, "cannot open /dev/netmap: %s", strerror(errno));
854 goto fail;
855 }
856
857 if (req)
858 d->req = *req;
859
860 if (!(new_flags & NM_OPEN_IFNAME)) {
861 if (nm_parse(ifname, d, errmsg) < 0)
862 goto fail;
863 }
864
865 d->req.nr_version = NETMAP_API;
866 d->req.nr_ringid &= NETMAP_RING_MASK;
867
868 /* optionally import info from parent */
869 if (IS_NETMAP_DESC(parent) && new_flags) {
870 if (new_flags & NM_OPEN_ARG1)
871 D("overriding ARG1 %d", parent->req.nr_arg1);
872 d->req.nr_arg1 = new_flags & NM_OPEN_ARG1 ?
873 parent->req.nr_arg1 : 4;
874 if (new_flags & NM_OPEN_ARG2) {
875 D("overriding ARG2 %d", parent->req.nr_arg2);
876 d->req.nr_arg2 = parent->req.nr_arg2;
877 }
878 if (new_flags & NM_OPEN_ARG3)
879 D("overriding ARG3 %d", parent->req.nr_arg3);
880 d->req.nr_arg3 = new_flags & NM_OPEN_ARG3 ?
881 parent->req.nr_arg3 : 0;
882 if (new_flags & NM_OPEN_RING_CFG) {
883 D("overriding RING_CFG");
884 d->req.nr_tx_slots = parent->req.nr_tx_slots;
885 d->req.nr_rx_slots = parent->req.nr_rx_slots;
886 d->req.nr_tx_rings = parent->req.nr_tx_rings;
887 d->req.nr_rx_rings = parent->req.nr_rx_rings;
888 }
889 if (new_flags & NM_OPEN_IFNAME) {
890 D("overriding ifname %s ringid 0x%x flags 0x%x",
891 parent->req.nr_name, parent->req.nr_ringid,
892 parent->req.nr_flags);
893 memcpy(d->req.nr_name, parent->req.nr_name,
894 sizeof(d->req.nr_name));
895 d->req.nr_ringid = parent->req.nr_ringid;
896 d->req.nr_flags = parent->req.nr_flags;
897 }
898 }
899 /* add the *XPOLL flags */
900 d->req.nr_ringid |= new_flags & (NETMAP_NO_TX_POLL | NETMAP_DO_RX_POLL);
901
902 if (ioctl(d->fd, NIOCREGIF, &d->req)) {
903 snprintf(errmsg, MAXERRMSG, "NIOCREGIF failed: %s", strerror(errno));
904 goto fail;
905 }
906
907 nr_reg = d->req.nr_flags & NR_REG_MASK;
908
909 if (nr_reg == NR_REG_SW) { /* host stack */
910 d->first_tx_ring = d->last_tx_ring = d->req.nr_tx_rings;
911 d->first_rx_ring = d->last_rx_ring = d->req.nr_rx_rings;
912 } else if (nr_reg == NR_REG_ALL_NIC) { /* only nic */
913 d->first_tx_ring = 0;
914 d->first_rx_ring = 0;
915 d->last_tx_ring = d->req.nr_tx_rings - 1;
916 d->last_rx_ring = d->req.nr_rx_rings - 1;
917 } else if (nr_reg == NR_REG_NIC_SW) {
918 d->first_tx_ring = 0;
919 d->first_rx_ring = 0;
920 d->last_tx_ring = d->req.nr_tx_rings;
921 d->last_rx_ring = d->req.nr_rx_rings;
922 } else if (nr_reg == NR_REG_ONE_NIC) {
923 /* XXX check validity */
924 d->first_tx_ring = d->last_tx_ring =
925 d->first_rx_ring = d->last_rx_ring = d->req.nr_ringid & NETMAP_RING_MASK;
926 } else { /* pipes */
927 d->first_tx_ring = d->last_tx_ring = 0;
928 d->first_rx_ring = d->last_rx_ring = 0;
929 }
930
931 /* if parent is defined, do nm_mmap() even if NM_OPEN_NO_MMAP is set */
932 if ((!(new_flags & NM_OPEN_NO_MMAP) || parent) && nm_mmap(d, parent)) {
933 snprintf(errmsg, MAXERRMSG, "mmap failed: %s", strerror(errno));
934 goto fail;
935 }
936
937
938 #ifdef DEBUG_NETMAP_USER
939 { /* debugging code */
940 int i;
941
942 D("%s tx %d .. %d %d rx %d .. %d %d", ifname,
943 d->first_tx_ring, d->last_tx_ring, d->req.nr_tx_rings,
944 d->first_rx_ring, d->last_rx_ring, d->req.nr_rx_rings);
945 for (i = 0; i <= d->req.nr_tx_rings; i++) {
946 struct netmap_ring *r = NETMAP_TXRING(d->nifp, i);
947 D("TX%d %p h %d c %d t %d", i, r, r->head, r->cur, r->tail);
948 }
949 for (i = 0; i <= d->req.nr_rx_rings; i++) {
950 struct netmap_ring *r = NETMAP_RXRING(d->nifp, i);
951 D("RX%d %p h %d c %d t %d", i, r, r->head, r->cur, r->tail);
952 }
953 }
954 #endif /* debugging */
955
956 d->cur_tx_ring = d->first_tx_ring;
957 d->cur_rx_ring = d->first_rx_ring;
958 return d;
959
960 fail:
961 nm_close(d);
962 if (errmsg[0])
963 D("%s %s", errmsg, ifname);
964 if (errno == 0)
965 errno = EINVAL;
966 return NULL;
967 }
968
969
970 static int
nm_close(struct nm_desc * d)971 nm_close(struct nm_desc *d)
972 {
973 /*
974 * ugly trick to avoid unused warnings
975 */
976 static void *__xxzt[] __attribute__ ((unused)) =
977 { (void *)nm_open, (void *)nm_inject,
978 (void *)nm_dispatch, (void *)nm_nextpkt } ;
979
980 if (d == NULL || d->self != d)
981 return EINVAL;
982 if (d->done_mmap && d->mem)
983 munmap(d->mem, d->memsize);
984 if (d->fd != -1) {
985 close(d->fd);
986 }
987
988 bzero((char *)d, sizeof(*d));
989 free(d);
990 return 0;
991 }
992
993
994 static int
nm_mmap(struct nm_desc * d,const struct nm_desc * parent)995 nm_mmap(struct nm_desc *d, const struct nm_desc *parent)
996 {
997 if (d->done_mmap)
998 return 0;
999
1000 if (IS_NETMAP_DESC(parent) && parent->mem &&
1001 parent->req.nr_arg2 == d->req.nr_arg2) {
1002 /* do not mmap, inherit from parent */
1003 D("do not mmap, inherit from parent");
1004 d->memsize = parent->memsize;
1005 d->mem = parent->mem;
1006 } else {
1007 /* XXX TODO: check if memsize is too large (or there is overflow) */
1008 d->memsize = d->req.nr_memsize;
1009 d->mem = mmap(0, d->memsize, PROT_WRITE | PROT_READ, MAP_SHARED,
1010 d->fd, 0);
1011 if (d->mem == MAP_FAILED) {
1012 goto fail;
1013 }
1014 d->done_mmap = 1;
1015 }
1016 {
1017 struct netmap_if *nifp = NETMAP_IF(d->mem, d->req.nr_offset);
1018 struct netmap_ring *r = NETMAP_RXRING(nifp, d->first_rx_ring);
1019 if ((void *)r == (void *)nifp) {
1020 /* the descriptor is open for TX only */
1021 r = NETMAP_TXRING(nifp, d->first_tx_ring);
1022 }
1023
1024 *(struct netmap_if **)(uintptr_t)&(d->nifp) = nifp;
1025 *(struct netmap_ring **)(uintptr_t)&d->some_ring = r;
1026 *(void **)(uintptr_t)&d->buf_start = NETMAP_BUF(r, 0);
1027 *(void **)(uintptr_t)&d->buf_end =
1028 (char *)d->mem + d->memsize;
1029 }
1030
1031 return 0;
1032
1033 fail:
1034 return EINVAL;
1035 }
1036
1037 /*
1038 * Same prototype as pcap_inject(), only need to cast.
1039 */
1040 static int
nm_inject(struct nm_desc * d,const void * buf,size_t size)1041 nm_inject(struct nm_desc *d, const void *buf, size_t size)
1042 {
1043 u_int c, n = d->last_tx_ring - d->first_tx_ring + 1,
1044 ri = d->cur_tx_ring;
1045
1046 for (c = 0; c < n ; c++, ri++) {
1047 /* compute current ring to use */
1048 struct netmap_ring *ring;
1049 uint32_t i, j, idx;
1050 size_t rem;
1051
1052 if (ri > d->last_tx_ring)
1053 ri = d->first_tx_ring;
1054 ring = NETMAP_TXRING(d->nifp, ri);
1055 rem = size;
1056 j = ring->cur;
1057 while (rem > ring->nr_buf_size && j != ring->tail) {
1058 rem -= ring->nr_buf_size;
1059 j = nm_ring_next(ring, j);
1060 }
1061 if (j == ring->tail && rem > 0)
1062 continue;
1063 i = ring->cur;
1064 while (i != j) {
1065 idx = ring->slot[i].buf_idx;
1066 ring->slot[i].len = ring->nr_buf_size;
1067 ring->slot[i].flags = NS_MOREFRAG;
1068 nm_pkt_copy(buf, NETMAP_BUF(ring, idx), ring->nr_buf_size);
1069 i = nm_ring_next(ring, i);
1070 buf = (const char *)buf + ring->nr_buf_size;
1071 }
1072 idx = ring->slot[i].buf_idx;
1073 ring->slot[i].len = rem;
1074 ring->slot[i].flags = 0;
1075 nm_pkt_copy(buf, NETMAP_BUF(ring, idx), rem);
1076 ring->head = ring->cur = nm_ring_next(ring, i);
1077 d->cur_tx_ring = ri;
1078 return size;
1079 }
1080 return 0; /* fail */
1081 }
1082
1083
1084 /*
1085 * Same prototype as pcap_dispatch(), only need to cast.
1086 */
1087 static int
nm_dispatch(struct nm_desc * d,int cnt,nm_cb_t cb,u_char * arg)1088 nm_dispatch(struct nm_desc *d, int cnt, nm_cb_t cb, u_char *arg)
1089 {
1090 int n = d->last_rx_ring - d->first_rx_ring + 1;
1091 int c, got = 0, ri = d->cur_rx_ring;
1092 d->hdr.buf = NULL;
1093 d->hdr.flags = NM_MORE_PKTS;
1094 d->hdr.d = d;
1095
1096 if (cnt == 0)
1097 cnt = -1;
1098 /* cnt == -1 means infinite, but rings have a finite amount
1099 * of buffers and the int is large enough that we never wrap,
1100 * so we can omit checking for -1
1101 */
1102 for (c=0; c < n && cnt != got; c++, ri++) {
1103 /* compute current ring to use */
1104 struct netmap_ring *ring;
1105
1106 if (ri > d->last_rx_ring)
1107 ri = d->first_rx_ring;
1108 ring = NETMAP_RXRING(d->nifp, ri);
1109 for ( ; !nm_ring_empty(ring) && cnt != got; got++) {
1110 u_int idx, i;
1111 u_char *oldbuf;
1112 struct netmap_slot *slot;
1113 if (d->hdr.buf) { /* from previous round */
1114 cb(arg, &d->hdr, d->hdr.buf);
1115 }
1116 i = ring->cur;
1117 slot = &ring->slot[i];
1118 idx = slot->buf_idx;
1119 /* d->cur_rx_ring doesn't change inside this loop, but
1120 * set it here, so it reflects d->hdr.buf's ring */
1121 d->cur_rx_ring = ri;
1122 d->hdr.slot = slot;
1123 oldbuf = d->hdr.buf = (u_char *)NETMAP_BUF(ring, idx);
1124 // __builtin_prefetch(buf);
1125 d->hdr.len = d->hdr.caplen = slot->len;
1126 while (slot->flags & NS_MOREFRAG) {
1127 u_char *nbuf;
1128 u_int oldlen = slot->len;
1129 i = nm_ring_next(ring, i);
1130 slot = &ring->slot[i];
1131 d->hdr.len += slot->len;
1132 nbuf = (u_char *)NETMAP_BUF(ring, slot->buf_idx);
1133 if (oldbuf != NULL && (uint32_t)(nbuf - oldbuf) == ring->nr_buf_size &&
1134 oldlen == ring->nr_buf_size) {
1135 d->hdr.caplen += slot->len;
1136 oldbuf = nbuf;
1137 } else {
1138 oldbuf = NULL;
1139 }
1140 }
1141 d->hdr.ts = ring->ts;
1142 ring->head = ring->cur = nm_ring_next(ring, i);
1143 }
1144 }
1145 if (d->hdr.buf) { /* from previous round */
1146 d->hdr.flags = 0;
1147 cb(arg, &d->hdr, d->hdr.buf);
1148 }
1149 return got;
1150 }
1151
1152 static u_char *
nm_nextpkt(struct nm_desc * d,struct nm_pkthdr * hdr)1153 nm_nextpkt(struct nm_desc *d, struct nm_pkthdr *hdr)
1154 {
1155 int ri = d->cur_rx_ring;
1156
1157 do {
1158 /* compute current ring to use */
1159 struct netmap_ring *ring = NETMAP_RXRING(d->nifp, ri);
1160 if (!nm_ring_empty(ring)) {
1161 u_int i = ring->cur;
1162 u_int idx = ring->slot[i].buf_idx;
1163 u_char *buf = (u_char *)NETMAP_BUF(ring, idx);
1164
1165 // __builtin_prefetch(buf);
1166 hdr->ts = ring->ts;
1167 hdr->len = hdr->caplen = ring->slot[i].len;
1168 ring->cur = nm_ring_next(ring, i);
1169 /* we could postpone advancing head if we want
1170 * to hold the buffer. This can be supported in
1171 * the future.
1172 */
1173 ring->head = ring->cur;
1174 d->cur_rx_ring = ri;
1175 return buf;
1176 }
1177 ri++;
1178 if (ri > d->last_rx_ring)
1179 ri = d->first_rx_ring;
1180 } while (ri != d->cur_rx_ring);
1181 return NULL; /* nothing found */
1182 }
1183
1184 #endif /* !HAVE_NETMAP_WITH_LIBS */
1185
1186 #endif /* NETMAP_WITH_LIBS */
1187
1188 #endif /* _NET_NETMAP_USER_H_ */
1189